Nanoindentation Study of Amorphous Metal Multilayered Thin Films
AbstractNanoindentation studies were preformed on amorphous metal, multilayered thin films containing alternating layers of Fe50Ti50 and Cu35Nb65 in order to investigate the mechanism for plastic deformation in metallic glass. Films with a total thickness of 1μm and bilayer repeat lengths ranging from 2 to 50 nm were magnetron sputter-deposited onto sapphire substrates. In contrast to many crystalline multilayered systems, where large hardness enhancements have been observed when the bilayer repeat length is reduced below about 10 nm, no significant hardness enhancement as a function of bilayer repeat length was observed in the Fe50Ti50/ Cu35Nb65 amorphous metal system. This result suggests that a dislocation–like mechanism for plastic deformation may not be appropriate for these amorphous metals.